I just had one built in 38 super. From what I understand, the advantage of the 9x23 is that the case is thicker to handle higher pressures and stacks better than the semi rimmed 38 super in the high cap mags. However, 38 super brass is more readily available and given the newly lowered PF to make major, I don't think that the stronger case of th 9x23 is important. I went with the super just because of availability. There is also something called the 38 super comp - I'm not sure if this is the 9x23 or something different. It is a cartridge the same as the 38 super but without the semi-rimmed design so it will stack better in the high caps and can be shot in a 38 super gun with a little adjustment of the extractor.
